1. Field of the Invention
The present invention relates to anchor and anchoring systems for securing arthroscopic or laparoscopic cannulas within puncture openings in the skin and more particularly to a flexible coil to be secured to the cannula device after being inserted through the puncture opening.
2. Description of the Related Art
Arthroscopic or endoscopic surgery is that surgery performed through minimally-invasive means, through limited incisions. The areas that are approachable by these techniques include any synovial joint; the abdominal and thoracic cavities; the mediastinum, epidural, pleural and subarachnoid spaces; heart ventricles and spinal cavities.
These endoscopic procedures provide a minimally invasive approach to many surgical procedures previously performed through traditional means. In the traditional approaches, surgery was performed by making a large incision over the area, followed by an exposure of the area in question by retracting or incising the soft tissues between the skin and the necessary area. In endoscopic surgery, a small puncture is made in the skin and a series of instruments are inserted by way of cannulas directly into the area. The cannula devices that are employed are usually tubular in shape and are of various sizes. Many have serrations, protruberances or threads at their tips (U.S. Pat. No. 5,217,441), in order to stabilize them in the soft tissues. None of the available designs, however, are effective in maintaining the cannula in proper position.
The reason for the lack of stability is that most commonly there is a medium that is used to distend the space. In the abdominal and thoracic cavities, it is CO2 gas; while in joints, it is saline solution. These materials cause the tissues to deform, subsequently allowing the cannula devices to move out of their original positions. The most common problem is that of having to re-insert the device back through the previously made tract. This becomes increasingly difficult with the use of more gas or fluid for distention.
There are several devices available that attempt to improve the stability of the cannula devices. One such example is U.S. Pat. No. 6,542,283 (Hopper), in which a universal balloon anchor is employed for stabilization of the cannula device. The complexity of the device, however, precludes its common employment as a result of its prohibitive price.
Many other devices are available that attempt to improve stability of the cannula by incorporating the stabilizing elements into the cannula. Some examples are U.S. Pat. No. 5,637,097 (Yoon), U.S. Pat. No. 5,197,971 (Bonutti), U.S. Pat. No. 5,002,557 (Hasson) and U.S. Pat. No. 5,882,340 (Yoon). All of these, while perhaps stabilizing the devices nicely, are not commonly employed as a result of their prohibitive cost, compared to the standard cannula devices currently available.